const s = Symbol();

console.log('s', s);
console.log('s', typeof s);


const s1 = Symbol('foo');
const s2 = Symbol('foo');
console.log('s1',s1);
console.log('s2',s2);
console.log('s1 === s2', s1 === s2);

// 可以定义私有成员
const name = Symbol();

const person = {
    [name]: 'aaa',
    say() {
        console.log('person[name]', this[name])
    }
};

person.say();